With COIN warfare being the chic today people thinking there is no fighting and killing that needs to be done. This however is incorrect in the take and hold phases an area or city must be taken from opposing forces. Taking these areas involves kinetic operations which kills the other team. The next phase is security which looks to defend the people against further insurgent or terrorist attacks. Victor Davis Hansen brings an interesting perspective to this argument. There is no telling how many jihadis were killed in Iraq in the years leading up to the success of the surge.
Counter terrorism and counter insurgency involve fighting and killing as well as taking the jihadists that are captured off of the streets forever which will involve incarceration at a facility such as Gitmo for a very long time. The reason for this incarceration is that the released jihadis are going back to their fighting ways.